The cancer cluster in children at Seascale in Cumbria is not related to their fathers' exposure to radiation while working in the nearby Sellafield nuclear plant, the government's committee on the medical aspects of radiation, Comare, concluded yesterday.

Comare's finding came 12 years after a department of health report caused a sensation by saying there was a link. The finding is a relief to the nuclear industry - but does not answer the question of why there is a cluster.

Comare reviewed studies showing that offspring of radiated workers in the UK and other countries were more likely to get leukaemia and non-Hodgkin's lymphoma - but there were similar findings in other industries.

There was a cancer cluster in Seascale, but it was not repeated in other children in the surrounding area where most workers lived. Comare concluded the cluster might be population mixing producing exposure to infectious diseases; however, pesticides or chemicals could also have been responsible. The government has accepted Comare's recommendation for more research into changes in the gene code of cells leading to childhood cancer.